Conventionally, it is known that in an operator device for an electronic musical instrument such as a keyboard instrument, a pair of fixed conductive portions are mounted on a printed circuit board, and a movable conductive portion that can be moved by an operator is provided so as to oppose these fixed contact patterns. In this type of operator device, as illustrated in FIG. 14 and the like of Patent Literature 1 noted below, the fixed conductive portions are widely known to be constituted by a pair of comb teeth-shaped contact patterns, and the movable conductive portion brings the pair of comb teeth-shaped fixed contact patterns into conduction, via itself, upon coming into contact with them. The fixed conductive portions and the movable conductive portion are generally constituted by carbon or the like. FIGS. 13A and 13B are schematic diagrams showing contact between typical comb teeth-shaped fixed contact patterns and a circular movable conductive portion.